Massively multiplayer online crowdsourced games (MMOCGs) are very smart. I’m not sure of their specific history, but one of the first to become well known was Twitch Plays Pokemon. Another popular and innovative game that is currently ongoing is The Button. A cardinal feature of MMOCGs is the complex, emergent culture that they generate.

A new genre of video game!
Criteria: runs in a browser using javascript, innocuously easy entry with a steady complexity curve (usually involving some sort of counter that starts at 0), mandatory time sinks, no social or pay to win features.
The best of these surprise the player and keep her just barely constantly doing something.